Systems, Methods and Devices for Embolic Protection

ABSTRACT

Embodiments of the present disclosure are directed to systems, methods and devices for providing embolic protection in a patient. In some embodiments, the device is configured for implantation in a body vessel including fluid flow. The device may assume, or be constrained to assume, an undeployed state and a deployed state. In the undeployed state, the device or a portion thereof has a substantially linear shape configured to reside in the lumen of a thin needle having a diameter of less than about 0.5 mm (for example), in the deployed state, the device has a primary axis. When the device is implanted the primary axis is approximately perpendicular to the fluid flow. In some embodiments, the device comprises a thin filament body. In the deployed state the filament takes a helical shape. Emboli that are larger than the distance between consecutive turns or windings of the helix are thus filtered by the device and are prevented from causing deleterious conditions such as stroke or pulmonary embolism. The device may be made of a super-elastic alloy. Thus, the device may transition between the undeployed and the deployed states without plastic deformation. Delivery systems and method for implanting such devices are also disclosed.

RELATED APPLICATIONS

This application claims priority to and benefit of each of U.S.provisional patent application No. 61/653,676, filed May 31, 2012,entitled, “Apparatus and Methods of Providing Embolic Protection in aPatient”, 61/693,979, filed Aug. 28, 2012, entitled, “Apparatus andMethod of Providing Embolic Protection in a Body Vessel of a Patient”,61/746,423, filed Dec. 27, 2012, entitled, “Apparatus and Method ofMonofilament Implant Delivery in a Body Vessel of a Patient”, and61/754,264, filed Jan. 18, 2013, entitled “Monofilament Implants andSystems for Delivery Thereof”, the entire disclosures of which areherein incorporated by reference in their entireties.

FIELD OF THE DISCLOSURE

The field of the present disclosure is embolic protection devices. Morespecifically, the field of the present disclosure is embolic protectionfor the prevention of brain stoke and/or pulmonary embolism.

BACKGROUND OF THE DISCLOSURE

Embolism is the event of lodging of an embolus (a detached intravascularmass) into a narrow vessel, which causes a blockage in a distant part ofthe body. Embolism can be classified as to whether it enters thecirculation in arteries or veins. Arterial embolism can start in theheart or in large arteries, and can cause occlusion and/or infarction inany part of the body. Embolus lodging in the brain from either the heartor the carotid arteries can cause an ischemic stroke. Venous embolism,which forms in systemic veins, can lodge in the lungs after passingthrough the right side of the heart. This deleterious condition is knownas pulmonary embolism.

Distal embolization can occur spontaneously or be induced bymanipulation of the heart, large arteries, or veins, either in thesetting of open surgery, or in the setting of endovascular manipulationsuch as balloon angioplasty or stenting.

Distal embolization can be prevented by pharmacological treatment(anti-coagulants). While effective, anticoagulants have the deleteriousside effect of high bleeding risk, which may be severe or evenlife-threatening. In addition, many patients do not tolerate wellanticoagulant medication and cannot enjoy the embolic protection that itmay render.

Distal embolization may also be prevented or by using mechanicalfiltering devices (distal embolic protection devices), which are placedbetween the embolic source and the distal vasculature. However, priorand current devices fail to adequately address the problem, and in fact,in many circumstances, cause problems (e.g., become occluded, migratefrom the implantation site, and the like).

SUMMARY OF THE DISCLOSURE

In some embodiments, an embolic protection device (filtering device) isprovided which includes a proximal end and a distal end, as well as anundeployed state and a deployed state.

In some embodiments, an embolic protection device is provided andcomprises a wire or a filament, which may be made of a super-elasticalloy (e.g., nitinol). The device, which has a proximal and a distalend, may assume two states—a constrained, undeployed, substantiallylinear state and an expanded, deployed state, which may have ahelical/helix shape. The device may be implanted within a blood vesselusing a delivery system comprising a rigid needle (which in someembodiments may be referred to also as a “tube”, both terms being usedinterchangeably, at least with respect to some embodiments, throughout)having an outer diameter of less than about 0.5 mm (about 1.5 French,0.02″) and a sharp distal end. The device may be preassembled within theneedle and positioned at the distal end, where it may be constrained toassume its undeployed, substantially linear state. A pusher, in a formof an elongated rod, may also be preassembled within the needle,extending from the proximal end of the needle to the proximal end of thedevice. The implantation of the device is performed by piercing the skinand underlying tissues and advancing the needle into a vessel underultrasound guidance. Within the vessel the device is exteriorized fromthe needle by pushing the pusher. After exteriorization of the devicefrom the needle, the device assumes the expanded deployed helical statesuch that the distal end resides within the vessel lumen and theproximal end resides outside the vessel lumen. The axis of the helixends up approximately perpendicular to the fluid flow within the vessel,and the windings or turns of the helix therefore exclude emboli whosesize is larger than the distance between consecutive helix turns.

In some embodiments, the axis of the helix (and/or the device ingeneral) may end up at a predetermined angle relative to the fluid flowwithin the vessel, which may be between approximately 20 degrees andabout 150 degrees, and in some embodiments, between about 30 degrees and120 degrees, in some embodiments, between about 45 degrees and 100degrees, and in some embodiments, between about 30 degrees and about 90degrees.

The term “substantially,” according to some embodiments, may be definedas near or proximate or about equal to, for example, a total amount,boundary or structure (and the like). In some embodiments, the term“substantially” may be defined as “essentially” (for example).

In some embodiments, a vascular embolic protection device for deploymentat an implantation site within a blood vessel is provided and mayinclude a filament having a length, proximal and distal ends and adiameter between about 0.025 mm and about 1 mm (and in some embodiments,between about 50 and 500 microns, for example), and is configured toinclude an undeployed state and a deployed state. In the undeployedstate, at least a portion of the device is configured to fit within thelumen of a delivery tube, and in the deployed state, the device includesa primary axis which is approximately perpendicular to the fluid flow.

In some embodiments, the primary axis of device may be positioned at apredetermined angle relative to the fluid flow within the vessel, whichmay be between approximately 20 degrees and about 150 degrees, and insome embodiments, between about 30 degrees and 120 degrees, in someembodiments, between about 45 degrees and 100 degrees, and in someembodiments, between about 30 degrees and about 90 degrees.

Some of the embodiments may include one or more of the followingfeatures:

-   -   a filament that has a length between about 7 mm and about 300        mm;    -   at least one of the tube end and the distal end of the device is        configured for puncturing the blood vessel in the vicinity of        the implantation site;    -   the length of a line segment connecting the proximal and the        distal ends in the deployed state is greater than or about equal        to the diameter of the blood vessel;    -   the filament includes a substantially circular cross-section;    -   the diameter of the filament is less than about 0.2 mm;    -   the device includes a first proximal segment near the proximal        end and a first distal segment near the distal end, and in the        deployed state, the segments are substantially collinear with        the primary axis;    -   in the deployed state, the filament further comprises a proximal        turn and a distal turn, and each turn resides in respective        plane, and at least one of the planes approximately includes the        primary axis;    -   the filament further comprises a proximal segment near the        proximal end, and in the deployed state the proximal segment is        substantially collinear with said primary axis;    -   in the deployed state, the filament further comprises a proximal        turn residing in a plane that approximately includes the primary        axis;    -   at substantially every point along its length the radius of        curvature exceeds a critical value equal to the diameter of the        filament divided by about twice the critical strain of the        material from which the filament is made. In some embodiments,        the critical value is greater than about 0.6 mm;    -   at least a portion of the filament in the undeployed state is        configured in the shape of a helix whose pitch is much larger        than its diameter;    -   in the deployed state the filament has the shape of a helix        comprising a plurality of turns, and depending upon the        embodiment: the plurality of turns vary in diameter, the number        of turns is between one and twenty, and/or a plurality of        windings approximately trace the shape of a spherical shell        having a diameter. In the case of the spherical shell, in some        embodiments, the diameter of the spherical shell is less than or        equal to the diameter of the vessel;    -   in the deployed state the filament has the shape of a helix        comprising a plurality of turns, and depending upon the        embodiment: the distance between consecutive windings is greater        than about 0.7 mm, or the distance between consecutive windings        is less than about 1.5 mm;    -   in the deployed state the filament has the shape of a helix        comprising a plurality of turns, and depending upon the        embodiment: the helix is compressed and exerts on the vessel        wall a force approximately collinear with the helix axis, or the        helix is not compressed;    -   the filament comprises a hollow lumen;    -   one or more of a radiopaque marker, an echogenic marker, a        radioactive marker, a magnetic marker, and a magnetic resonance        marker;    -   the filament may be made from at least one of: a metal, a        plastic, a natural polymer, a shape memory alloy, a super        elastic alloy, a biodegradable material, a bioresorbable        material, and a bioabsorbable material;    -   an end piece arranged on at least one of the proximal end and        the distal end, where, depending upon the embodiment:        -   each of the end pieces comprises at least one of a            radiopaque marker, an echogenic marker, a radioactive            marker, a magnetic marker, a magnetic resonance marker, an            anchor, a non-traumatic tip, a bearing, and a retrieval            knob,        -   each of the end pieces may be configured with an undeployed            and a deployed state;        -   at least one of the end pieces may comprise an anchor, where            the anchor may comprise at least one of a loop, a roughened            surface, a barb, a micro-barb, a hook, a bulge, and a            material configured to enlarge upon contact with an aqueous            environment;        -   at least one of the end pieces may each separately be            integral with the filament;        -   the radiopaque marker may comprise gold, platinum, a            combination thereof and/or any other heavy metal (or            combination thereof);        -   the echogenic marker may comprise one or more of a            micro-bubble, a micro-bubble coating, and a cornerstone            reflector;        -   the bearing may comprise housing and an axle, which may be            configured to rotate in said housing with any degree of            friction, and may be integral with the filament;        -   the bearing may be configured to release accumulated torsion            or to prevent the build-up of torsion in the filament;    -   the filament may be substantially straight in the deployed state        (and in some embodiments, in the undeployed state);    -   the shape of the filament may be substantially similar in both        the undeployed and the deployed states;    -   the device may further comprise two or more filaments, where        each filament has a length, a diameter, a proximal filament end,        and a distal filament end, as such, depending upon the        embodiment, the filaments may joined at the proximal end and at        the distal end of the device, and the two or more filaments each        have a helical shape.

In some embodiments, a delivery device for delivering one and/or anotherdevice embodiments (for example) is provided, and may comprise a needlehaving a lumen, a sharp distal end, and an outer diameter less thanabout 1 mm, and a pusher slidable within the needle. The delivery devicemay also include at least one of a needle handle and a pusher handle.

In some embodiments, a method for implanting an embolic protectiondevice in a patient's vessel containing fluid flow is provided and mayinclude one or more, and in some embodiments, several, and, in someembodiments, all of the following steps: providing a needle having alumen and a sharp distal end, providing a pusher slidable within thelumen of the needle, providing a device having a distal end, anundeployed state, and a deployed state having a primary axis, where atleast a portion of the device is loaded within the lumen, making apuncture in a wall of the vessel using the sharp distal end of theneedle or the distal end of the device, and exteriorizing the devicethrough said needle and said puncture by advancing the pusher,retracting the needle, or both, such that said primary axis ends upapproximately perpendicular to the fluid flow direction.

In some of such method embodiments, the method may further include thestep of retracting the needle and the pusher from the patient, and/ormaking a second puncture at a location approximately diametricallyopposed said puncture.

The device in such embodiments may be anchored proximate the puncturefollowing exteriorization, and/or may be anchored at locations proximatethe puncture and the second puncture following exteriorization.

Some method embodiments may further include the step of retrieving theembolic protection device from the patient's vessel.

Accordingly, some of the embodiments disclosed herein are configured toprovide embolic protection against stroke or pulmonary embolism, in anyof an artery, a vein, an aorta, a common carotid artery, an internalcarotid artery, a subclavian artery, a brachiocephalic artery, a renalartery, a vertebral artery, a superficial femoral vein, a deep femoralvein, a popliteal vein, an iliac vein, an inferior vena cava, and asuperior vena cava. Such embolic protection may be permanent, ortemporary, depending upon the embodiment.

In some embodiments, a retrieval apparatus for retrieving an implantedembolic protection device is provided and may comprise an extractionsheath having a lumen and a sharp end configured to pierce skin and tointernalize said embolic protection device, and a grasper configured toirreversibly attach to said proximal end of the embolic protectiondevice and to fit inside said lumen of said extraction sheath. Thefiltering device may be extracted from a patient through said extractionsheath.

In some embodiments, a device for occluding and/or ligating a patient'svessel is provided and may comprise an undeployed state and a deployedstate, a filament comprising a proximal segment, a distal segment, and aseparation point disposed between said proximal and distal segments, adistal anchor disposed at a distal end of said distal segment, and aslidable proximal anchor. The proximal anchor may be located in anundeployed state proximally to the separation point and in the deployedstate distally to the separation point, and the proximal filamentsegment may be disconnected from the distal filament segment by applyingmechanical and/or electrical energy to the separation point.

In some embodiments, a system for occluding and/or ligating a patient'svessel is provided and may comprise a device for occluding and/orligating a patient's vessel (according to any one or another of suchdisclosed embodiments), a push tube configured to slidably receive theproximal segment of the filament and to push the slidable proximalanchor over the filament towards the distal anchor, and a deliverycatheter comprising a hollow needle of less than about 1 mm in diameter,configured to slidably receive the push tube.

In some embodiments, a method for vessel ligation is provided and maycomprise providing a system for occluding and/or ligating a patient'svessel (according to any such disclosed embodiments), puncturing avessel wall at two diametrically-opposed sites, retracting the needleaway from the device distal end allowing the distal anchor to engagetissue in its vicinity, and optionally further retracting the needlewherein the implant is exteriorized within the lumen of said vessel. Insome embodiments, upon the needle end being retracted to a pointexternal to the vessel lumen, the proximal anchor engages tissue in itsvicinity. Further, in some embodiments, the method includes sliding theproximal anchor towards the distal anchor, resulting in externalcompression of the vessel and partial or complete adhering of the twoopposing vessel walls. In some embodiments, one or more of the followingsteps may be performed: applying mechanical and/or electrical energy tothe separation point, thereby separating the proximal filament segmentfrom the rest of the device, and, exteriorizing the proximal filamentsegment from the patient.

In some embodiments, a method for embolic protection is provided and mayinclude one or more of the following steps (in some embodiments, aplurality of these steps, and further still, in some embodiments, all ofthe following steps): providing a filtering device having an undeployedstate and a deployed state having a primary axis, providing a deliverydevice comprising a needle having a lumen, said device configured topuncture tissue, making a puncture in a wall of a vessel using saiddelivery device, exteriorizing the filtering device through saidpuncture such that said primary axis ends up approximately perpendicularto the fluid flow within said vessel.

In some embodiments, an embolic protection device is provided for use ina patient's vessel, where the device may comprise proximal and distalends, an undeployed state, and a deployed state having a primary axis.The device may be configured to pass through a needle whiletransitioning from the undeployed state to the deployed state, and inthe deployed state, the primary axis may be approximately perpendicularto the fluid flow in the patient's vessel.

In some embodiments, an embolic protection device for use in a patient'svessel is provided, where the vessel includes a fluid flow and a lumen.The device may include proximal and distal ends, an undeployed state,and a deployed state having a primary axis. In the deployed state, theprimary axis may be approximately perpendicular to the fluid flow and atleast one of the proximal and distal ends resides exteriorly to thelumen.

In some embodiments, an embolic protection device for use in a patient'svessel is provided, and may comprise a filament having proximal anddistal ends, an undeployed state, and a deployed state approximatelyshaped as a helix. In the deployed state the axis of the helix isroughly perpendicular to the fluid flow.

In some embodiments, an embolic protection device for use in a patient'svessel is provided. The device may comprise proximal and distal ends, anundeployed state, and a deployed state having a primary axis. In thedeployed state the primary axis is approximately perpendicular to thelongitudinal axis of the patient's vessel.

In some embodiments, a method for providing embolic protection in apatient is provided, where the method may include implanting a filamenthaving a helical shape in a vessel of the patient, where vessel includesa fluid flow, such that the axis of the helix is approximatelyperpendicular to the fluid flow direction.

In some embodiments, in an undeployed state, the device, or a portionthereof, may assume or be constrained to assume, a substantially linearstate. In the deployed state, the device may assume any shaperesembling, or tracing the shell of, a body of revolution. In someembodiments, the axis of this body of revolution may be referred to asthe “primary axis.” For example, the device may assume, in the deployedstate, a helical shape, where the primary axis is the axis of the helix.The device may be deployed in a body vessel having a fluid flow suchthat the primary axis is approximately perpendicular to the direction ofthe fluid flow.

In embodiments where the filament may possess a helical shape in thedeployed state, the helical shape may comprise a plurality of windingsor turns. The primary axis of the deployed state may roughly coincidewith the axis of the helical shape. In some embodiments, the pluralityof windings may roughly trace the shape of a spherical shell having adiameter. This diameter may be slightly less than the diameter of thetarget vessel.

In some embodiments, the deployed state of the device may be configuredto trap emboli that might be present in the fluid flow. If, for example,the vessel is a carotid artery supplying blood to the brain, then thedevice may be configured to trap emboli originating, for example, in theheart and aorta and prevent them from causing brain stroke. If forexample, the vessel is a femoral vein ultimately supplying blood to thelungs, then the device may be configured to trap emboli that originate,for example, in calf veins and may cause pulmonary embolism.

In some embodiments, in an undeployed, substantially linear state, thedevice may be configured to fit in the lumen of a thin tube or needle.The outer diameter of the tube or the needle may be less than about 1mm, or even less than about 0.5 mm (for example). The puncture orpunctures made by the needle in body tissue may be configured to berelatively small such that the risk of bleeding is minimal. Thepunctures, in some embodiments, may self-seal and self-heal.

In some embodiments, embolic protection devices of the presentdisclosure may comprise a single filament. The length of the filament,in some embodiments, may be in the range of about 7 mm to about 300 mm.The diameter of the filament, in some embodiments, may be less thanabout 0.2 mm.

In some embodiments, the distance between consecutive turns may exceedabout 0.7 mm. In some embodiments, the distance between consecutiveturns may be less than about 1.5 mm. In some embodiments particularlysuitable for protection against pulmonary embolism, the distance betweenconsecutive windings may be greater than about 1.5 mm.

In some embodiments, emboli originating upstream of the device may befiltered by the device because they cannot pass between consecutiveturns. In this way the device provides embolic protection.

In some embodiment, the filament comprises a hollow lumen. This makesthe filament more visible by ultrasound imaging. In some embodiments,the device may comprise one or more of: a radiopaque marker, anechogenic marker, a radioactive marker, a magnetic marker, and amagnetic resonance marker.

In some embodiments, the filament may be made of a metal, a plastic, anatural polymer, a shape memory alloy, a super-elastic alloy, abiodegradable material, a bioresorbable material or a bioabsorbablematerial.

In some embodiments, the device may comprise two or more filaments. Thefilaments may be joined at their ends. The filaments may each have ahelical shape. The filaments may possess an equal phase offset withrespect to each other. For example, an embodiment consisting of threefilaments is possible in which consecutive filaments are mutuallyphase-offset by 120 degrees.

In some embodiments, embolic protection devices according to the presentdisclosure may be delivered using a delivery device comprising: a needlehaving a pusher slidable within the needle, a lumen, a sharp distal end,and an outer diameter less than about 1 mm.

In some embodiments, an embolic protection device is loaded in anundeployed state in the distal end of the delivery device. The pusher isloaded in the proximal end of the delivery device such that within theneedle the distal end of the pusher is in contact with the proximal endof the device. The delivery device is used to deploy the embolicprotection device in a patient: A puncture is made in a wall of thetarget vessel using the sharp distal end of the needle or the distal endof the device; the device is exteriorized into the lumen of the vesselby pushing the pusher, retracting the needle, or both, such that theprimary axis of the device ends up approximately perpendicular to thefluid flow in the vessel; and retracting the pusher and the needle fromthe patient.

In some embodiments, deployment of the device entails making a secondpuncture at a location on the vessel wall that is approximatelydiametrically opposed to the location of the first puncture.

In some embodiments, the device is anchored externally to the vessel ata location proximate the puncture. In some embodiments, the device isalso anchored externally to the vessel at a location proximate to thesecond puncture.

In some embodiments, the device is implanted in any of an artery, avein, an aorta, a common carotid artery, an internal carotid artery, asubclavian artery, a brachiocephalic artery, a renal artery, a vertebralartery, a superficial femoral vein, a deep femoral vein, a poplitealvein, an iliac vein, an inferior vena cava, and a superior vena cava.

In some embodiments, an implanted device may be retrieved from theimplantation site. A retrieval apparatus according to some embodimentsmay comprise an extraction sheath and a grasper. The extraction sheathmay have a sharp end, which is configured to pierce skin. The extractionsheath may also be configured to internalize the embolic protectiondevice. The grasper may be configured to catch the proximal end of theimplanted device and to fit inside the lumen of the extraction sheath.The retrieval apparatus may thus be used to extract the implanted devicethrough the extraction sheath.

In some embodiments, embolic protection may be provided by ligating oroccluding a target vessel. An occlusion or ligation device according tosome embodiments may comprise an undeployed and a deployed state; afilament comprising a proximal segment and a distal segment, which arecapable of being disconnected from each other at a separation point; adistal anchor disposed at the distal end; and a slidable proximalanchor. The proximal anchor is located in the undeployed stateproximally to the separation point. In the deployed state the proximalanchor is located distally to the separation point. The filament may beseparated into two parts by applying mechanical or electrical energy tothe separation point.

In some embodiments, a system for occluding or ligating a target vesselmay comprise the occlusion/ligation device, a push tube configured toslidably receive the proximal segment of the filament and to push theslidable proximal anchor over the filament towards the distal anchor,and a delivery catheter comprising a needle configured to slidablyreceive the push tube and the device.

In some embodiments, vessel occlusion or ligation may be brought aboutby: providing the ligation system; puncturing the vessel wall at twodiametrically-opposed sites; retracting the needle away from the deviceallowing the distal anchor to engage tissue in its vicinity; furtherretracting the needle wherein the device is exteriorized within thelumen of the vessel, and, upon the needle being retracted to a pointexternal to the vessel lumen, the proximal anchor engages tissue in itsvicinity; sliding the proximal anchor towards the distal anchor,resulting in external compression of the vessel and adhering or bringingtogether the two opposing vessel walls; applying mechanical orelectrical energy to the separation point, thereby separating theproximal part of the filament from the remainder of the device; and,retracting the proximal part of the filament from the patient.

Advantages of Some of the Embodiments

The following advantages are realized by one and/or another of thedisclosed embodiments:

-   -   providing embolic protection in patients unsuitable for        anticoagulant drugs;    -   obviating the need for anticoagulant drugs and their        side-effects in patients at high risk for embolic disease;    -   protection against emboli originating anywhere in the arterial        circulation proximally to the neck, as opposed to left atrial        appendage occluders that target emboli originating in the left        atrial appendage alone;    -   reduced risk of thrombus formation as compared to mesh-based        devices: some embodiments according to the present disclosure        have a thin monofilament body lacking wire crossings, thereby        providing less resistance to blood flow, less flow obstruction        and stagnation, and subsequent activation of the blood clotting        cascade;    -   reduced risk of clogging due to excessive endothelial cell        growth as compared to tubular mesh based devices: some        embodiments of the present disclosure have far less contact area        with vessel walls;    -   better physical fit to conform with changes in vessel diameter        because some embodiments according to the present disclosure        have a helical design that is particularly good at coping with        tensile and/or compressive forces;    -   less invasive than embolic protection devices that are delivered        by catheterization, and therefore, reduced risk of        complications. For example, some embodiments may be delivered        through a very thin needle having a diameter of less than about        0.5 mm, as compared to catheters that have a diameter of about        2 mm. As a result, punctures made during the delivery of        embodiments according to the present disclosure self-seal and        self-heal, as opposed to the far larger and more traumatic        catheter punctures;    -   delivery is lower in cost and simpler. For example, embolic        protection devices according to some embodiments may be        implanted bedside under ultrasound guidance and do not require a        catheterization laboratory, fluoroscopy, or highly skilled        personnel;    -   easily retrievable using minimally invasive technique, which        does not require that the target vessel be punctured again.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be better understood with reference to theaccompanying drawings and subsequently provided detailed description:

FIGS. 1A and 1B respectively depict undeployed and deployed states of amonofilament filtering device according to some embodiments of thepresent disclosure.

FIGS. 1C and 1D respectively depict undeployed and deployed states of amonofilament filtering device according to some embodiments of thepresent disclosure, which lack the distal-most turn and segment of thedevice of FIG. 1B.

FIGS. 2A and 2B respectively depict undeployed and deployed states of amonofilament filtering device including end pieces according to someembodiments of the present disclosure.

FIGS. 2C and 2D respectively depict undeployed and deployed states of amonofilament filtering device including an end piece and lacking thedistal-most turn and segment of the device of FIG. 2B, according to someembodiments of the present disclosure.

FIGS. 3A and 3B depict a schematic rendering of undeployed and deployedstates of an end piece according to some embodiments of the presentdisclosure.

FIGS. 4A and 4B respectively depict undeployed and deployed states of anend piece according to some embodiments of the present disclosure.

FIGS. 5A and 5B respectively depict undeployed and deployed states ofanother end piece according to some embodiments of the presentdisclosure.

FIGS. 6A and 6B respectively depict undeployed and deployed states of aspring-shaped monofilament embolic protection device including two endpieces according to some embodiments of the present disclosure.

FIGS. 6C and 6D respectively depict undeployed and deployed states of aspring-shaped monofilament embolic protection device having one endpiece according to some embodiments of the present disclosure.

FIGS. 7A-7C depict straight monofilament embolic protection devicesrespectively including zero, one, and two end pieces according to someembodiments of the present disclosure.

FIGS. 8A and 8B respectively depict undeployed and the deployed statesof an embolic protection device comprising more than one filamentaccording to some embodiments of the present disclosure.

FIG. 8C is a cross-sectional view of the deployed state of the embolicprotection device of FIGS. 8A and 8B.

FIGS. 9A and 9B depict a monofilament filtering device in operation,according to some embodiments of the present disclosure.

FIGS. 10A-10E depict a system and method according to some embodimentsof the present disclosure, which are intended for implanting amonofilament filtering device according to some embodiments of thepresent disclosure.

FIGS. 11A-11D depict a system and method according to some embodimentsof the present disclosure, which are intended for implanting anothermonofilament filtering device according to some embodiments of thepresent disclosure.

FIGS. 12A and 12B depict the components of an apparatus for retrieving afiltering device according to some embodiments of the present disclosure

FIGS. 13A-13F depict a method according to some embodiments of thepresent disclosure, which is intended for retrieving a filtering deviceaccording to some embodiments of the present disclosure.

FIGS. 14A and 14B respectively depict undeployed and deployed states ofa vessel occlusion device according to some embodiments of the presentdisclosure.

FIGS. 15A and 15B respectively depict a perpendicular cross section of abody vessel before and after the implantation of the occlusion device ofFIGS. 14A and 14B.

FIGS. 16A-16E depict a system and method according to some embodimentsof the present disclosure, which are intended for implanting anocclusion device according to some embodiments of the presentdisclosure.

DETAILED DESCRIPTION OF SOME OF THE EMBODIMENTS

Reference is now made to FIG. 1A, which depicts some embodiments of anundeployed state of a filtering device (embolic protection device) ofthe present disclosure. Filtering device 10, configured to be implantedin a body vessel, can be a filament of cylindrical shape. However, crosssectional shapes other than circular are also possible.

In some embodiments, the length of the filament from which filteringdevice 10 is made may be greater than the diameter of the body vesselfor which it is intended. Thus, if implanting the filtering device in avein or an artery having a diameter of about 7 mm, then the length ofthe filament may be, for example, in the range of about 7 to about 300mm.

In some embodiments, the diameter of the filament from which filteringdevice 10 is made may be substantially less than its length. Forimplantation into a blood vessel, the filament diameter may be chosen ofa size sufficient so as to not cause blood coagulation. Therefore, thefilament diameter, according to some embodiments, is less than about 0.5mm, and more specifically less than about 0.2 mm, and even morespecifically, less than about 0.15 mm.

In some embodiments, an undeployed state of device 10 may assume, or beconstrained to assume, any shape that fits within the lumen of a tubehaving a length L and an inner diameter D such that L is much greaterthan D. (the terms “substantially linear” or “substantially straight” asused herein refer to all such shapes.) For example, length L may be inthe range of about 10 to about 300 mm, whereas the diameter D may be inthe range of about 0.05 to about 0.7 mm.

In some embodiments, an undeployed state of device 10 may assume, forexample, the shape of a substantially straight line, as in FIG. 1A. Insome embodiments, a portion or a segment of the device, but not theentire device, in the undeployed state may assume, or be constrained toassume, the shape of a substantially straight line. It may also assume,or be constrained to assume, a shape resembling a helix in which thepitch (that is, the vertical distance between consecutive windings) maybe much larger than the helix diameter (that is, the diameter of thesmallest cylinder in which the helix might fit).

Reference is now made to FIG. 1B, which depicts an embodiment of thedeployed state of a filtering device of the present disclosure. In thedeployed state, filtering device 10 may assume the shape of a helix(spring or spiral). This helix shape may have windings or turns thatvary in diameter. The windings may, but do not have to, approximatelytrace the shape of a spherical shell. The helix shape possesses aprimary axis, which may roughly coincide with the axis of the helix.

More generally, the deployed state of the device may trace any shaperesembling, or residing in the shell of, a body of revolution. A body ofrevolution is defined by revolving a plane shape around an axis in theplane. By the “primary axis” of the deployed shape of the device, insome embodiments, it is meant to be a line roughly coinciding with thisaxis in the plane. For example, whenever the deployed shape of thedevice has the helical shape of FIG. 1B, the primary axis roughlycoincides with the axis of the helix.

In some embodiments, having the deployed shape of the device resemble,or reside in the shell of, a body of revolution has the advantage thatno control of the orientation of the device around the primary axis needbe maintained during implantation. This makes for a robust, simple, andreproducible implantation procedure.

The deployed length L′ of filtering device 10 may be greater than thediameter of the body vessel for which it is intended. Thus, ifimplanting the filtering device in a vein or an artery having a diameterof about 7 mm, then the deployed length L′ may be, for example, in therange of about 7 to about 20 mm. The deployed diameter D′ of filteringdevice 10 may be less than or approximately equal to the diameter of thetarget vessel at the implantation site. For example, if implanting thefiltering device in a vein or an artery having a diameter of about 7 mmthen the diameter D′ may be in the range of about 5 mm to about 8 mm.

In some embodiments, in the deployed state, the primary axis roughlycoincides with the line segment connecting distal end 11 and proximalend 12 of device 10. The primary axis may be substantially perpendicularto the plane approximately defined by some of the helix turns orwindings. The distal segment 13 and the proximal segment 14 of device 10may be substantially collinear with the primary axis.

The distal turn 15 of device 10 may reside in a plane containing theprimary axis. Likewise, the proximal turn 16 in device 10 may alsoreside in a plane containing the primary axis. The two planes may, butdo not have to, be one and the same. All of the remaining turns indevice 10 may reside in planes that are approximately, but notnecessarily exactly, perpendicular to the primary axis.

Device 10 may be configured such that in the deployed state the radiusof curvature at any point along its length is greater than or equal to acritical value RE. This critical value may be assigned such that thestrain suffered at any point of device 10 is less than or equal to thecritical strain required to bring about an elastic-to-plastictransformation upon transition from the deployed to the undeployedstate. In this way device 10 may be able to transition from the deployedshape to the undeployed shape and back without substantial differencebetween the initial and final deployed shapes. For example, if thefilament from which device 10 is made has a circular cross sectionhaving diameter d, and the material from which device 10 is made hascritical strain e, then the critical value R_(c) is given by R_(c)=d/2ε.Therefore, if, for example, device 10 is made from super-elastic nitinolhaving critical strain a of about 0.08, and the filament diameter d isabout 0.15 mm, then the critical radius of curvature will be roughlyabout 0.94 mm.

Accordingly, the deployed state of device 10 may be configured to trapembolic material having typical size that is larger than the distance 8between consecutive windings. Whenever device 10 is configured toprotect a patient from major embolic stroke, device 10 is made to trapemboli exceeding about 1-2 mm in size. In this case the distance 8 maybe less than about 1.5 mm, and, more specifically, in the range of about0.7 mm and about 1.5 mm. Even more specifically, the distance 8 mayreside in the range of about 0.3 mm and about 1.2 mm. Whenever device 10is configured to protect a patient from pulmonary embolism, device 10may be made to trap emboli exceeding about 5 mm in size. In this casethe distance 8 may be less than about 3 mm, and, more specifically, inthe range of about 1.5 mm and about 5 mm.

Filtering device 10 may be configured to be relatively stiff or, in someembodiments, relatively flexible. Alternatively, filtering device 10 maybe configured to assume any degree of flexibility. In the deployedshape, filtering device 10 may possess either a low spring constant or ahigh spring constant. Alternatively, in the deployed state, filteringdevice 10 may be configured to any value for its corresponding springconstant.

Filtering device 10, according to some embodiments, may be configured asa solid filament. Alternatively, it may be configured as a tube having ahollow lumen, or as a tube having its ends closed-off, thereby leavingan elongated air-space inside filtering device 10. Leaving an air-spaceinside filtering device 10 may have the advantage of making filteringdevice 10 more echogenic and therefore more highly visible by ultrasoundimaging. Filtering device 10 may possess one or more echogenic markerand/or one or more radiopaque marker anywhere along its length.

Filtering device 10 may be made from any suitable biocompatiblematerial, such as metal, plastic, polymers, or natural polymer, orcombination thereof. Suitable metals include (for example): steel,stainless steel (e.g., 305, 316 L), gold, platinum, cobalt chromiumalloys, shape memory and/or super-elastic alloys (e.g., nitinol),titanium alloys, tantalum, or any combination thereof. Suitable plasticsinclude (for example) silicones, polyethylene, polytetrafluoroethylene,polyvinyl chloride, polyurethane, polycarbonate, and any combinationthereof. Suitable polymers include shape memory polymers orsuper-elastic polymers. Suitable natural polymers may include collagen,elastin, silk and combinations thereof.

In some embodiments, filtering device 10 may be made from an absorbable,biodegradable, or bioresorbable material, such as a bioresorbablepolymer or a bioresorbable metal. Suitable bioresorbable polymersinclude polyL-lactide, polyD,L-lactide, polyglycolide, polyε-caprolactone. 50/50 D,L lactide/glycolide, 82/18 L-lactide/glycolide,70/30 L-lactide/ε-caprolactone, 85/15 L-lactide/glycolide, 10/90L-lactide/glycolide, 80/20 L-lactide/D,L-lactide, or any combinationthereof. Suitable bioresorbable metals can include magnesium alloy.

Some embodiments of filtering devices according the present disclosureare substantially similar to filtering device 10, except for one or moreof the following differences: part or all of distal segment 13 may belacking, part or all of distal turn 15 may be lacking, part or all ofproximal segment 14 may be lacking, and part or all of proximal turn 16may be lacking.

For example, FIG. 1C depicts an undeployed state and FIG. 1D depicts adeployed state of a filtering device 17 substantially similar tofiltering device 10 but lacking distal segment 13 and distal turn 15.Device 17 may be particularly suitable for implantation through a singlepuncture in a target vessel. In such an embodiment, all device partsexcept perhaps for proximal segment 14 and proximal end 12 may lieentirely inside the vessel lumen or walls. Distal end 11 may comprise anon-traumatic tip (such as, for example, a polished ball), configured tosafely appose the inner wall of the vessel, or a short, sharp endconfigured to anchor in the vessel wall without breaching it completely.

The helical portion of device 17 may have a length that is shorter, thesame as, or longer than the diameter of the vessel for which it isintended. A longer length may facilitate apposition of the distal end ofthe device against the vessel wall. A shorter length may have theadvantage of minimizing contact between the device and the vessel wall.

Reference is now made to FIGS. 2A and 2B, which respectively representundeployed and deployed states of another embodiment of the filteringdevice of the present disclosure. Filtering device 20 is substantiallysimilar to filtering device 10 of FIGS. 1A and 1B: device 20 comprises afilament 21 that is substantially similar to the filament from whichdevice 10 is made. However, device 20 may also comprise one or more of afirst end piece 22 residing at one end of filament 21, and a second endpiece 23 residing at the opposite end of filament 21.

In an undeployed state (FIG. 2A), filtering device 20, includingend-pieces 22 and 23, may be configured to reside in the lumen of ahollow needle. Upon exteriorization from such a needle (FIG. 2B),filtering device 22 may assume a deployed shape substantially similar tothat of filtering device 10, and end-pieces 22 and 23 may, but do nothave to, assume a shape that is different from their shape in theundeployed state of device 20.

Reference is now made to FIGS. 2C and 2D, which respectively representundeployed and deployed states of another embodiment of the filteringdevice of the present disclosure. Filtering device 24 is substantiallysimilar to filtering device 17 of FIGS. 1C and 1D: device 24 comprises afilament 21 that is substantially similar to the filament from whichdevice 17 is made. However, device 24 may also comprise an end piece 22residing at its proximal end.

In an undeployed state (FIG. 2C), filtering device 24, includingend-piece 22, may be configured to reside in the lumen of a hollowneedle. Upon exteriorization from such a needle (FIG. 2D), filteringdevice 24 may assume a deployed shape substantially similar to that offiltering device 17, and end-piece 22 may, but does not have to, assumea shape that is different from its shape in the undeployed state ofdevice 24.

Reference is now made to FIG. 3A, which depicts the undeployed state andthe components that each of end pieces 22 and 23 may separatelycomprise. End pieces 22 and 23 may each separately comprise one or moreof the following: an anchor 31, a radiopaque marker 32, an echogenicmarker 33, a bearing 34, and a retrieval knob 37. End pieces 22 and 23may each also separately comprise a non-traumatic tip, such as aball-shaped protrusion made of metal. End pieces 22 and 23 may also eachseparately comprise one or more of a radioactive marker, a magneticmarker, and a magnetic resonance marker.

End pieces 22 and 23 may each separately be integral with filament 21.They may be made to assume undeployed and deployed shapes that aredifferent. For example, the deployed shape may comprise loops or turnsconfigured to anchor device 24 in tissue. Anchor 31 may comprise anymeans known in the art for attaching a foreign body to living tissue.For example anchor 31 may comprise a roughened surface, a bulge, a mass,one or more barbs, one or more micro-barbs, one or more hook, a hydrogelbulge configured to enlarge upon contact with an aqueous environment, ortheir likes. Anchor 31 may, but does not have to, be configured tochange its shape upon transition from the undeployed state to thedeployed state of devices 20 or 24 (FIG. 3B). Anchor 31 may comprise abiocompatible metal, a biocompatible polymer, a shape memory material, asuper elastic material (e.g. super elastic nitinol) or any combinationthereof.

Whenever anchor 31 is of the shape-changing variety, it may be made, forexample, of a super elastic material. In its free state, that is, in thestate in which no (or little) force is exerted on it by its externalenvironment, the anchor will assume the deployed state depicted in FIG.3B. Whenever anchor 31 is housed in, for example, a hollow needle of asufficient bore, its moving parts will retain sufficient elastic energyas to cause them to assume their deployed shape upon release. Thus, uponexteriorization from the needle at the implantation site, anchor 31 willtransition from its undeployed state of FIG. 3A, to the deployed stateof FIG. 3B.

Radiopaque marker 32 may comprise a biocompatible radiopaque material,such as gold or platinum.

Echogenic marker 33 may comprise a biocompatible echogenic material,such as tantalum. The marker 33 may comprise an echogenic coatingcomprising air micro-bubbles, cornerstone reflectors, or any other meansknown in the art to increase echogenicity. Upon transition from theundeployed state to the deployed state of device 20 or device 24, marker33 may retain its shape. Alternatively, the shape of marker 33 maychange upon transition from the undeployed to the deployed state.

Bearing 34 may comprise an axle 35 and a housing 36. Axle 35 may beconfigured to freely rotate within housing 36. Alternatively, axle 35may be configured to rotate within housing 36 with any pre-specifieddegree of friction. Axle 35 may be rigidly connected to an end offilament 21. Alternatively, axle 35 may be integral with an end offilament 21.

Housing 36 may be rigidly connected to anchor 31. In this way, uponapplication of torque to axle 35, the axle may rotate inside housing 36,and housing 36 may remain substantially motionless with respect to thetissue in which it resides.

Bearing 34 may comprise any mechanism known in the art for constrainingrelative motion between the axle and the housing to only a desiredmotion. For example, bearing 34 may comprise a plain bearing, a bushing,a journal bearing, a sleeve bearing, a rifle bearing, a rolling-elementbearing, a jewel bearing, and a flexure bearing.

Embodiments comprising a retrieval knob (or, for example, othergraspable means, such as a bulb, a loop, or a protrusion) areparticularly suited for temporary or permanent implantation, whereasembodiments lacking a retrieval knob are particularly suited forpermanent implantation.

Retrieval knob 37 is any contraption capable of being grasped bygrasping devices such as a grasper, a hook, or a snare. Retrieval knob37 may be, for example, a bulb, a loop, or a protrusion. It may be madefrom a plastic, a metal, a natural polymer, or a biodegradable polymer.Knob 37 may be configured to be grasped by any retrieval mechanismcapable of connecting to the knob and applying force to the knob so asto cause the retrieval of a device comprising it, such as 20 or 24, fromthe tissue in which it is deployed. Suitable retrieval mechanismsinclude, for example, graspers, hooks and snares.

We note that different components in each end piece need not bephysically distinct: for example, the housing of the bearing may alsoserve as an anchor, the radiopaque marker and the echogenic marker maybe one and the same, the bearing may serve to provide radiopacity orechogenicity, and so forth. To illustrate this point, reference is nowmade FIGS. 4A and 4B, which represent an embodiment of end piece 23according to the present disclosure, and to FIGS. 5A and 5B, whichrepresent an embodiment of end piece 22 according to the presentdisclosure.

FIG. 4A depicts an undeployed state of a particular embodiment of endpiece 23, according to the present disclosure. End piece 23 may comprisean external cylinder 41, prongs 45, a proximal ring 42, a distal ring43, a ball 44, and axle 35. External cylinder 41 and prongs 45 may beintegral with each other. They may be made from a shape memory orsuper-elastic alloy, such as nitinol. Upon transition of, for example,device 20 from the undeployed to the deployed state, prongs 45 extendoutwards, thereby anchoring end piece 23 in the tissue in which it isimplanted. The proximal part of cylinder 41, proximal ring 42, anddistal ring 43 may be rigidly connected to each other to form a bearinghousing 36. Rings 42 and 43 may each be made from a radiopaque and orechogenic material, such as gold, platinum, or tantalum. The end offilament 21 may be rigidly connected to, and may be integral with, ball44, which may be made from metal, a polymer, an alloy, a shape memorymaterial, or a super elastic material. Together, the end of filament 21and ball 44 provide a bearing axle 35. The axle 35 is free to rotatewithin housing 36 more or less around the housing's principal axis.However, in some embodiments, rings 42 and 43 substantially prevent allother relative motions of axle 35 with respect to housing 36. Housing 36and axle 35 together provide a bearing.

FIG. 5A depicts an undeployed state of some embodiments of end piece 22,according to the present disclosure. End piece 22 may comprise anexternal cylinder 51, and prongs 52, which may be integral with thecylinder. Both the prongs and the cylinder may be made from a shapememory or super-elastic material, such as nitinol. External cylinder 51may be rigidly connected to the end of filament 21 using any connectionmeans known in the art, such as crimping, welding, soldering, gluing,and their likes. The external surface of cylinder 51 may be coated withan echogenic coating, or carry cornerstone reflectors. In this way, endpiece 22 may comprise an anchor and an echogenic marker. However, theembodiment of end piece 22 presented in FIGS. 5A and 5B does notcomprise a bearing or a retrieval knob.

Reference is now made to FIGS. 6A and 6B, which depict undeployed anddeployed states, respectively, of an embolic protection device accordingto some embodiments of the present disclosure. Device 60 issubstantially similar to device 17. Filament 61 assumes a spring shapein the deployed state. The spring coils of device 60 need not reside ingeometrical planes that are approximately perpendicular to the primaryaxis of the device (the line connecting end pieces 22 and 23). Inaddition, the coils of device 60 need not trace the shape of a sphericalshell. Embodiments in which the diameter of the spring shape traced bythe device are less than the diameter of the vessel for which it isintended are possible, thereby minimizing vessel wall contact. Suchembodiments may be well suited for implantation in veins for the purposeof preventing pulmonary embolism: the dangerous emboli are fairly large(>5 mm in diameter, >10 mm in length). Thus, efficient capture of emboliis possible even if filament 61 has little or no wall contact throughoutits length.

The spring shape of filament 61 may accommodate large changes in thediameter of the vessel for which it is intended by allowing filament 61to lengthen or shorten in accordance with the growth or shrinkage invessel diameter. This is particularly important when device 60 isimplanted in a peripheral vein, such as a femoral vein, which may dilateby up to a factor of two in response to, for example, Valsalva maneuver.

Reference is now made to FIGS. 6C and 6D, which respectively depictundeployed and deployed states of a filtering device 62 substantiallysimilar to filtering device 60, but lacking end piece 23. Device 62 maybe particularly suitable for implantation through a single puncture in atarget vessel. In such an embodiment, all device parts except perhapsfor proximal end piece 22 may lie entirely inside the vessel lumen orwalls. Distal end 63 may comprise a non-traumatic tip (such as, forexample, a polished ball), configured to safely appose the inner wall ofthe vessel, or a short, sharp end configured to anchor in the vesselwall without breaching it completely.

Reference is now made to FIGS. 7A-7C, which depict embodiments of anembolic protection device according to some embodiments of the presentdisclosure. These embodiments are particularly suitable for implantationin locations where bisecting a vessel's cross section into two roughlyequal halves can result in adequate embolic protection. For example, thedevices of FIGS. 7A-7C may be implanted in a leg vein in order toprevent deep vein thrombi from embolizing to the lungs. They may also beimplanted, for example, in a vertebral artery supplying blood to theposterior brain circulation, thereby preventing emboli traveling to thebrain through the vertebral artery from causing posterior circulationstroke.

Device 70 of FIG. 7A comprises is a filament 71 that may besubstantially similar to the filament of device 10 in terms of diameter,flexibility, structure (solid or hollow), and material composition.Filament 71 may have a fixed or a variable diameter along its length.The length of device 70 may be greater, roughly the same as, or smallerthan the diameter of the vessel in which it is implanted. The attributethat distinguishes device 70 over device 10 is this: device 70 issubstantially straight in both its undeployed and its deployed states.

Device 72 of FIG. 7B is substantially similar to device 70, except forthe following major difference: device 72 comprises in addition tofilament 71 an end-piece 22. End piece 22 may be situated at theproximal end of filament 71, and may be integral with it. Alternatively,end piece 22 and filament 71 may be joined by any chemical, physical, ormechanical means known in the art, such as gluing or crimping. End piece22 may comprise one or more of an anchor, an echogenic marker, aradiopaque marker, and a retrieval knob. Distal end 73 of device 72 maybe sharpened as to be suitable for creating punctures in tissue. Distalend 73 may also comprise a non-traumatic tip.

Device 74 of FIG. 7C is substantially similar to device 70, except forthe following major difference: device 74 comprises in addition tofilament 71 an end-piece 22 at one of its ends and an end piece 23 atits opposite end. End pieces 22 and 23 may each be integral withfilament 71, or each may be joined to filament 71 by any chemical,physical, or mechanical means known in the art, such as gluing orcrimping. End pieces 22 and 23 may each separately comprise one or moreof an anchor, an echogenic marker, a radiopaque marker, and a retrievalknob.

Reference is now made to FIGS. 8A-8C. FIG. BA depicts an embodiment 80of the filtering device of the present disclosure. Filtering device 80may comprise a filter body 83 and ends 81 and 82. Filter body 83 maycomprise three filtering filaments 84, 85, and 86. FIG. 8A depictsfiltering device 80 at its undeployed state. In this state, filteringdevice 80 is configured to fit in the lumen of a hollow needle, whereits shape is constrained by the force applied by the walls of theneedle. FIG. 8B depicts filtering device 80 in its deployed state.Because in the deployed state there is little force to constrain thefiltering filaments to their collinear configuration of FIG. 8A, thefiltering filaments 84, 85, and 86 come apart, assuming a crosssectional configuration as in FIG. 8C.

Elongated filtering element 80 may be made of a shape memory alloy, ashape memory polymer, a metal, a polymer, a biodegradable,bioabsorbable, or bioresorbable polymer, or a biodegradable,bioabsorbable, or bioresorbable metal. Each of the ends 81 and 82 offiltering device 80 may be unitary with filter body 83, or may bedistinct, such as end pieces 22 and 23 as described above.

Filter body 83 of filtering device 80 is not limited to include anyparticular number of filtering filaments. Any number of filaments ispossible, and an embodiment having three filtering filaments waspresented above only as a representative example. Two, four, five, andsix (or higher) filament configurations are also possible. Connectionpoints and connecting bridges between distinct filtering filaments andacross different points in the same filament are also feasible. Anembodiment in which each filament by itself assumes the shape of aspring or a coil is feasible. Thus, an embodiment comprising, forexample, three helix-shaped filaments, wherein the second helix isrotated with respect to the first helix by 120 degrees and the thirdhelix is rotated with respect to the first helix by 240 degrees isfeasible. A “bird's nest” design, in which one or more filteringfilament is “multiply entangled” when in the deployed state, is alsopossible. A net-shape, such as a basket-shaped like a fishing net isalso possible. A central filament centered in a ring, with the ringbeing configured to appose the vessel wall, is also possible.

In yet another embodiment of the present disclosure, the filteringdevice has one or more protrusions extending from a main branchfilament, such that one or more side branches are formed (for example).These protrusions may have the form of free ends (brush like) or closedshapes with both ends connected to the main branch filament. In someembodiments, there are one or more end piece, such as end pieces 22 and23, located at the distal and proximal ends of the filament.

The filtering devices of the present disclosure and their components maybe manufactured, for example, by industrial processes known in the art,comprising one or more of the following: injection molding, extrusion,forming on a mandrel, heat treatment, and surface treatment.

Reference is now made to FIGS. 9A and 9B, which respectively depict aside view and a cross-sectional view of a body vessel in which device 20is implanted and operating. Device 20 is implanted in body vessel 90such that its primary axis, that is, the axis extending from end piece22 to end piece 23, is approximately perpendicular to the longitudinalaxis of vessel 90, and roughly bisects a perpendicular cross section ofthe vessel. Whenever vessel 90 contains a flowing fluid, the primaryaxis of device 20 will be approximately perpendicular to the directionof fluid flow (and to the longitudinal axis of the vessel). Thus, if,for example, vessel 90 is an artery or a vein, the primary axis ofdevice 20 will be approximately perpendicular to the direction of bloodflow.

Embolus 91 is stopped by device 20 whenever its size is too large topass through the openings defined by device 20 and the lumen of vessel90. This size exclusion mechanism enables device 20 to protect variousend-organs supplied by vessel 90 from embolic damage. For example, ifvessel 90 is an artery supplying the brain, such as, for example, anaorta, a common carotid artery, an internal carotid artery, a subclavianartery, a brachiocephalic artery, or a vertebral artery, device 20 mayprotect the brain from stroke. If vessel 90 is a deep vein then device20 may protect the lungs from pulmonary embolism.

The principle of operation (embolic protection) of embodiments 10, 17,24, 60, 62, 70, 72, 74, and 80, as well as all other embodimentsmentioned above, is substantially the same as for device 20: all devicesare implanted such that their primary axis is roughly perpendicular tothe direction of fluid flow in the target vessel, and the primary axisapproximately divides a perpendicular cross section of the vessel toapproximately equal halves. Emboli too big to pass through openingsdefined by the device and the vessel lumen are filtered by sizeexclusion.

Reference is now made to FIGS. 10A-10E, which illustrate a system and amethod for providing embolic protection according to some embodiments ofthe present disclosure. The system and method are particularly suitablefor delivering a filtering device 20 comprising at least one end pieceincorporating a bearing. The at least one end piece incorporating abearing enables torsion in filament 21 of device 20 to be controllablyreleased during device implantation, thereby providing for a controlledand robust implantation procedure. However, the system and method ofFIGS. 10A-10E do not require that at least one end-piece of device 20comprise a bearing: they are suitable also for embodiments of device 20that lack a bearing.

FIG. 10A depicts a system 100 configured to implant a filtering device20 in a body vessel 101. System 100 comprises a hollow needle 102, apusher 103, and filtering device 20. Taken together, the hollow needleand the pusher can be a delivery device. Hollow needle 102 has a sharpend 112 configured to pierce skin 104, subcutaneous tissue 105, and bodyvessel 101 of a patient. Needle 102 may have a needle handle 106 locatedat its proximal end 107. The needle handle 106 may be rigidly connectedto needle 102. Pusher 103 may have a pusher handle 108 located at itsproximal end.

Hollow needle 102 may have a very small inner and outer diameter. Forexample, if the maximal collapsed diameter of undeployed filteringdevice 20 is about 100 to about 400 microns, the inner diameter ofhollow needle 102 may be in the range of about 100 to about 900 microns,and the outer diameter of hollow needle 102 may be in the range of about200 to about 1000 microns. More specifically, the inner diameter ofhollow needle 102 may be in the range of about 200 to about 400 microns,and the outer diameter of needle 102 may be in the range of about 300 toabout 600 microns. Thus, the punctures made by hollow needle 102 in apatient's tissue may be sufficiently small (about 100 to about 900microns) as to be self-sealing.

Hollow needle 102 may be made from any suitable biocompatible material,such as, for example, stainless steel. Pusher 103 may also be made froma metal such as stainless steel. Handles 106 and 108 may be made fromplastic.

In the absence of external load, filtering device 20, in someembodiments, assumes the deployed shape of FIG. 2B. To transform device20 to an undeployed state, it may be stretched by applying axial forceat both its ends using a special jig (not shown). The stretched devicemay then be inserted into the lumen of needle 102 by sliding the needleover the stretched, undeployed device. Twisting device 20 before orduring insertion into needle 102 is also possible.

Both filtering device 20 and pusher 103 may be slidable within the lumenof hollow needle 102. Prior to deployment, filtering device 20 islocated inside the lumen of needle 102 near its distal end 112. Thedistal end 109 of pusher 103 is also located inside the lumen of hollowneedle 102. The distal end 109 of pusher 103 is in contact with theproximal end of end piece 22 of device 20. After deployment, as depictedin FIG. 10E, filtering device 20 may be exteriorized from hollow needle102, and the distal end 109 of pusher 103 roughly coincides with distalend 112 of hollow needle 102.

The implantation of filtering device 20 in body vessel 101 may proceedas follows. First, a physician determines that it is desirable toimplant filtering device 20 in body vessel 101. Under the guidance of asuitable imaging modality (not shown), such as, for example, ultrasound,high resolution ultrasound, CT scanning, or without Imaging guidance atall, the operator punctures skin 104 adjacent to vessel 101 using thesharp end 112 of needle 102. Note that system 100 is in theconfiguration depicted in FIG. 10A, that is, with filtering device 20housed in its undeployed state near the distal end of hollow needle 102.The operator then carefully advances delivery device 100 through thesubcutaneous tissue, and transversely punctures vessel 101 atapproximately diametrically-opposed sites 110 and 111. The firstpuncture 110 of vessel 101 is made on its side closer to skin 104(proximal side), and the second puncture 111 is made on thediametrically-opposite side (distal side). The sharp end 112 of needle102 may then be advanced a few more millimeters interiorly into thepatient, so that end piece 23 may be exterior to the lumen of vessel101. This situation is depicted in FIG. 10A.

Next, the operator holds pusher 103 substantially motionless whileretracting hollow needle 102 backwards, away from the patient. This canbe done with the aid of handles 106 and 108. In this way, end piece 23of device 20 is exteriorized from needle 102. It then assumes itsdeployed state in the tissue proximate second puncture 111, therebyanchoring the distal end 23 of device 20 in the tissue. The needle maythen be retracted until its distal end 112 roughly coincides withproximal puncture 110. This situation is depicted in FIG. 10B.

To exteriorize the remainder of device 20 from hollow needle 102, theoperator advances pusher 103 towards the distal end 112 of needle 102while holding the needle still. As device 20 is exteriorized from theneedle, it gradually assumes its deployed, spring-like shape. Thissituation is depicted in FIG. 10C.

In some embodiments, exteriorizing device 20 may create torque along theprincipal axis of end-piece 23. In such embodiments, it may beadvantageous for end piece 23 to comprise a bearing 34, thereby enablingthe strain (torsion) pre-existing in filament 21 to release. This mayalso prevent torsion from building up during the exteriorizationprocess. In such embodiments, the distal end of filament 21 rotates withend piece 23 as a pivot point while device 20 is exteriorized. Theoperator stops pushing the pusher once filament 21 is essentiallyexteriorized from needle 102 into the lumen of vessel 101, and end piece22 is situated, still inside the lumen of needle 102, proximate itsimplantation site. The situation is then as depicted in FIG. 10D.

In some embodiments, to complete the implantation procedure, theoperator holds pusher 103 steady while retracting needle 102 over thepusher. This causes the end piece 22 to be exteriorized at itsimplantation site and assume its deployed shape. Once the entire device20 is exteriorized and implanted in its deployed state, both needle 102and pusher 103 are exteriorized from the patient's body. This completesthe implantation procedure for some embodiments, as depicted in FIG.10E. Note that for some embodiments, because both the filtering device20 and hollow needle 102 are of a sufficiently small diameter, all ofthe holes and the punctures made in body tissues during the proceduremay be self-sealing. Therefore, the suturing or sealing of holes andpunctures thus made is unnecessary. If it is determined that one or moreadditional filtering devices should be implanted in one or moreadditional implantation sites the procedure may be performed again,essentially as described above.

Implantation systems comprising devices 10, 60, 70, 74, and 80 areobtainable by exchanging device 20 in system 100 for any of thesedevices. The implantation methods corresponding to these systems thusobtained are substantially similar to the method corresponding to system100. Therefore, the detailed description of these systems and methods isomitted.

Reference is now made to FIGS. 11A-11D, which illustrate a method forproviding embolic protection and a system for delivering an embolicprotection device according to some embodiments of the presentdisclosure. The system and method are particularly suitable fordelivering a filtering device 24 comprising one end piece 22 at itsproximal end. A single proximal puncture of the target vessel isrequired, as opposed to two diametrically opposed punctures as in themethod corresponding to system 100.

FIG. 11A depicts a system 113 configured to implant a filtering device24 in a body vessel 101. System 113 is substantially similar to system100, except that filtering device 20 is exchanged for filtering device24.

In some embodiments, the implantation of filtering device 24 in bodyvessel 101 may proceed as follows. First, a physician determines that itis desirable to implant filtering device 24 in body vessel 101. Underthe guidance of a suitable imaging modality (not shown), such as, forexample, ultrasound, high resolution ultrasound, or CT scanning, orwithout imaging guidance at all, the operator punctures skin 104adjacent to vessel 101 using the sharp end 112 of needle 102. Theoperator then carefully advances system 113 through the subcutaneoustissue, and punctures vessel 101 using the sharp end 112 of needle 102.The orientation of the needle is roughly perpendicular to the wall ofvessel 101 at the point of contact (puncture 110) of the needle and thevessel wall. The operator then slightly advances system 113 such thatsharp end 112 of needle 102 slightly protrudes into the lumen of vessel101. This situation is depicted in FIG. 11A.

Next, the operator exteriorizes filament 21 of device from needle 102 byholding needle 102 in place and advancing pusher 103. As filament 21 isexteriorized from the needle, its exteriorized portion assumes itsdeployed shape in the lumen of vessel 101. The distal tip 11 of device24 approximately traces the deployed helical shape of device 24 asfilament 21 is exteriorized. This situation is depicted in FIG. 11B.

As proximal turn 16 of device 24 is exteriorized from needle 102, theprimary axis (that is, roughly the line segment connecting distal tip 11and end piece 22) becomes collinear with needle 102. As a result, theprimary axis of device 24 ends up approximately perpendicular to thefluid flow in vessel 101, and approximately bisects a perpendicularcross section of vessel 101. This situation is depicted in FIG. 11C.

In some embodiments, to complete the implantation procedure the operatorholds pusher 103 steady while retracting needle 102 over the pusher.This causes end piece 22 to be exteriorized at its implantation siteproximal puncture 110 and assume its deployed shape. Once the entiredevice 24 is exteriorized and implanted in its deployed state, bothneedle 102 and pusher 103 are exteriorized from the patient's body. Thiscompletes the implantation procedure, as depicted in FIG. 11D. Note thatin some embodiments, because both the filtering device 24 and hollowneedle 102 are of a sufficiently small diameter, all of the holes andthe punctures made in body tissues during the procedure may beself-sealing. Therefore, the suturing or sealing of holes and puncturesthus made is unnecessary. If it is determined that one or moreadditional filtering devices should be implanted in one or moreadditional implantation sites the procedure may be performed again,essentially as described above.

We note that in embodiments according to the present disclosure in whichdistal tip 11 is sharp, it is possible to puncture the wall of vessel101 using tip 11 instead of sharp end 112 of needle 102. In fact, in allof the embodiments of filtering devices according to the presentdisclosure in which the distal tip of the device is sharp, it ispossible to create one or more punctures in the vessel wall using tip 11instead of the sharp end of needle 102.

Implantation systems comprising devices 17, 62, and 72 are obtainable byexchanging device 24 in system 113 for any of these devices. Theimplantation methods corresponding to the systems thus obtained aresubstantially similar to the method corresponding to system 113.Therefore, a detailed description of these systems and methods isomitted.

In some embodiments, delivery devices in which needle 102 has a variablediameter are provided.

In some embodiments, the implantation of a filtering device according tothe present disclosure results in the distal end of the device apposingthe vessel wall at a location roughly diametrically opposed to thepuncture site. The distal end (or distal end-piece, where applicable)may partially or completely penetrate the vessel wall. The proximal end(or proximal end-piece, where applicable) may be located outside thelumen of the vessel, across the wall of the vessel, or inside the lumenof the vessel. Any wall penetration depth (none, partial, complete) ispossible in the deployed state of embolic protection devices accordingto the present disclosure.

Reference is now made to FIGS. 12A and 12B, which depict components of aretrieval apparatus according to some embodiments according to thepresent disclosure. The retrieval apparatus is particularly suitable forminimally-invasive explantation and retrieval of embolic protectiondevices according to some embodiments, which comprise a proximalend-piece having a retrieval knob.

FIG. 12A depicts extraction sheath 120, which comprises a hollow sheath123 having a lumen and a sharp end 122, and a handle 121. The internaldiameter of hollow sheath 123 is configured to be larger than thediameter of retrieval knob 37 of proximal end-piece 22 of device 60. (Wenote that device 60 was chosen by way of example: any embodiment of afiltering device according to the present disclosure and comprising aretrieval knob may be retrieved using the retrieval apparatus of FIGS.12A and 12B.)

FIG. 12B depicts a grasper 124, which comprises hollow sheath 126 andhandle 125. The distal end of sheath 126 comprises springy, flexibleleaflets 127, which may bend towards the inner walls of lumen 128 ofsheath 126, yet are limited by each other in bending towards the centerof lumen 128.

Reference is now made to FIGS. 13A-13F, which depict some methods ofretrieval according the some embodiments of the present disclosure.First, it is determined by the operator that is desirable to retrieve,for example, an embolic protection device 60, which comprises a proximalend-piece having a retrieval knob 37, from its implantation site in abody vessel. Then, using a suitable imaging modality such as ultrasound,high resolution ultrasound, CT, or MRI, the operator punctures thepatient's skin 104 using extraction sheath 120, and advances the distaltip 122 of hollow sheath 123 over knob 37 of proximal end-piece 22. Thissituation is depicted in FIG. 13A. Note that distal tip 122 may resideeither externally to the vessel, as depicted in FIG. 13A, in the vesselwall, or in the lumen.

Next the operator advances grasper 124 inside the lumen of hollow sheath123, while hollow sheath 123 is maintained in place. The distal end ofsheath 126 then touches knob 37 of end-piece 22. Flexible springyleaflets 127 are then pushed outwards towards the walls of lumen 128 byknob 37. This situation is depicted in FIG. 13B.

The operator then continues to push grasper 124 while holding extractionsheath 120 in place. The proximal ends of springy leaflets 127 thenextend distally to the distal end of knob 37. The knob is now insidelumen 128 of sheath 126. Due to the “ratchet” effect between theleaflets and the knob, grasper 124 can no longer be retracted over knob37. It is irreversibly attached to knob 37. This situation is depictedin FIG. 13C.

Next, the operator maintains extraction sheath 120 in place whileretracting grasper 124. Flexible leaflets 127 thus pull on knob 37,thereby forcing end piece 22 into its undeployed state, straighteningdevice 60, and retracting it into the lumen of hollow sheath 123. Thissituation is depicted in FIG. 13D. Further retraction of grasper 124brings about the situation depicted in FIG. 13E: The pulling forcegenerated by retracting grasper 124 is transmitted through straightenedfilament 61 thereby causing end piece 23 to assume its undeployed shapeand ultimately to retract into the lumen of hollow sheath 123.

Finally, extraction sheath 120, extractor 124, and device 60 are jointlyretracted by the operator from the patient's body. The small punctures110 and 111 in vessel 101 self-seal. The retrieval procedure is over.

It will be noted that an apparatus for retracting retrievableembodiments of devices 20, 24, 62, 72, 74, and 80, and theircorresponding retrieval methods, are substantially similar to theretrieval apparatus and method described for device 60. A detaileddescription will therefore be omitted.

Reference is now made to FIGS. 14A and 14B, which depict undeployed anddeployed states, respectively, of a body-vessel occlusion deviceaccording to some embodiments of the present disclosure. An occlusiondevice of this type provides embolic protection by completely occludingthe target vessel in which it is implanted. It may be particularlyuseful, for example, in preventing the embolization of sclerosantutilized in a saphenous vein in the course of varicose vein treatment.

Occlusion device 140 of FIG. 14A may comprise a filament 141, a proximalanchor 142, and a distal anchor 143. Filament 141 may be separated intoa proximal part 144 and a distal part 145 at separation point 146. Theproximal and distal parts 144 and 145 are initially connected atseparation point 146, and may be disconnected upon the application ofexternal force or signal. A removable handle 149 may optionally beattached to proximal part 144 at its proximal end.

The initial connection between parts 144 and 145 may be mechanical. Forexample, part 144 may screw into part 145, and disconnection of theparts may be brought about by unscrewing them. Alternatively, filament141 may comprise a conducting core cladded with an insulating layer atevery point along its length except for separation point 146. When it isdesired to separate parts 144 and 145, electrical current from anexternal source (not shown) is run through filament 141, thereby causingelectrolysis and subsequent disconnection of parts 144 and 145 atseparation point 146.

Proximal anchor 142 may be slidable over filament 141. For example,proximal anchor 142 may comprise a slidable element 148 configured toslide over filament 141. Slidable element 148 may comprise a lockingmechanism that fixes it in a desired location along filament 141.

In its undeployed state, occlusion device 140 may be configured toreside in the lumen of a fine needle, substantially collinear with thelumen of the needle. The anchors 143 and 142 assume their undeployedconfiguration when device 140 is in its undeployed state.

The undeployed length of occlusion device 140 may be in the range ofseveral centimeters to about 100 cm. The diameter of occlusion device140 may preferably be less than about 1.0 mm. In particular, thediameter of occlusion device 140 may preferably be less than about 0.5mm, and even more particularly, less than about 0.2 mm.

Separation point 146 may be between about 1 mm and about 30 mm from thedistal end of occlusion device 140.

In the deployed state of occlusion device 140 (FIG. 14B), anchors 142and 143 may be in their deployed configuration. Anchor 142 may be movedtowards anchor 143 such that the distance between them is typicallybetween about 1 mm and about 10 mm. The most proximal point of anchor142 is distal to separation point 146. Proximal part 144 of filament 141is separated from distal part 145. Thus, the deployed state of occlusiondevice 140 comprises distal part 145 of filament 141 and no longercomprises the proximal part 144.

Occlusion device 140 may be configured to be relatively stiff or, insome embodiments, relatively flexible. Alternatively, occlusion device140 may be configured to assume any degree of flexibility. Stiffness anddiameter along the length of filament 140 may be variable.

Occlusion device 140, according to some embodiments of the presentdisclosure, may be configured as a solid filament. Alternatively, it maybe configured as a tube having a hollow lumen, or as a tube having itsends closed-off, thereby leaving an elongated air-space inside occlusiondevice 140. Leaving an air-space inside occlusion device 140 may havethe advantage of making occlusion device 140 more echogenic andtherefore more highly visible by ultrasound imaging. Occlusion device140 may possess an echogenic marker or a radiopaque marker.

Occlusion device 140 may be made, for example, from any of the materialsthat devices 10 or 20 may be made of, as described earlier in thisdocument.

Reference is now made to FIG. 15A, which depicts a schematiccross-sectional view of a blood vessel before implantation of occlusiondevice 140. Reference Is also made to FIG. 15B, which depicts aschematic cross-sectional view of the blood vessel after implantation ofdevice 140.

FIG. 15A shows the circular cross-section of a patent blood vessel 150,such as an artery or a vein, in which blood is free to flow in vessellumen 151. Suitable veins may be, for example, perforators of the greatsaphenous vein. Upon implantation of occlusion device 140 in bloodvessel 150 (FIG. 5B), anchors 143 and 142, which are brought closetogether, push against opposite sides of the vessel wall, therebyflattening a perpendicular cross section of the vessel. As a result,lumen 151 disappears, or substantially disappears. Thus, occlusiondevice 140 causes vessel 150 to become either totally or substantiallyoccluded.

Reference is now made to FIGS. 16A-16E, which depict a method for vesselocclusion and an apparatus for implanting a (partial or total) occlusiondevice according to some embodiments of the present disclosure. FIG. 16Adepicts a delivery device 160 configured to implant occlusion device 140in body vessel 150. Delivery device 160 comprises a hollow needle 161,push tube 163, and occlusion device 140. Hollow needle 161 has a sharpend 164 configured to pierce skin 104, subcutaneous tissue 105, and bodyvessel 150 of a patient. Needle 161 may have a needle handle 165 locatedat its proximal end 166. The needle handle 165 may be rigidly connectedto needle 161. Push tube 163 may have a push tube handle 168. The pushtube handle 168 may be rigidly connected to push tube 163.

Hollow needle 161 may have a very small inner and outer diameter. Forexample, if the maximal collapsed diameter of undeployed occlusiondevice 140 is 200 microns, the inner diameter of hollow needle 161 maybe in the range of 200-600 microns, and the outer diameter of hollowneedle 161 may be in the range of 300-800 microns. Thus, the puncturesmade by hollow needle 161 in a patient's tissue may be sufficientlysmall (100-900 microns) as to be self-sealing.

Hollow needle 161 may be made from any suitable biocompatible material,such as, for example, stainless steel. Push tube 163 may also be madefrom a metal such as stainless steel. Handles 165 and 168 may be madefrom plastic.

Occlusion device 140 and push tube 163 may both be slidable within thelumen of hollow needle 161. Occlusion device 140 may also be slidablewithin the lumen of push tube 163.

Prior to deployment, occlusion device 140 may be slidably receivedinside the lumen of push tube 163. In some embodiments, the distal end169 of push tube 163 is in contact with the proximal end of slidableelement 147 of anchor 142. Both occlusion device 140 and push tube 163are slidably received in the lumen of needle 161. The distal anchor 143of occlusion device 140 is located near the sharp end 164 of needle 161.

In some embodiments, the implantation of occlusion device 140 in bodyvessel 150 may proceed as follows: First, an operator determines that itis desirable to implant occlusion device 140 in body vessel 150. Underthe guidance of a suitable imaging modality (not shown), such as, forexample, ultrasound, high resolution ultrasound, or CT scanning, orwithout imaging guidance at all, the operator punctures skin 104adjacent to vessel 150 using the sharp end 164 of needle 161. Note thatdelivery device 160 is in the configuration depicted in FIG. 16A, thatis, with the distal end of occlusion device 140 near the distal end ofhollow needle 161, and in its undeployed, substantially-linear,substantially-straight wire state. The operator then carefully advancesdelivery device 160 through the subcutaneous tissue 105, andtransversely punctures vessel 140 at approximately diametrically-opposedsites 170 and 171. The first puncture 170 of vessel 150 is made on itsside closer to skin 104, and the second puncture 171 is made on thediametrically-opposite side. Note that the second puncture 171 may beeither complete or partial: Sharp end 164 of needle 161 may completelytraverse the wall of vessel 150, or alternatively, only breach theinside (lumen side), but not the outside of the wall. The sharp end 164of needle 161 may then be advanced a few more millimeters interiorlyinto the patient. This situation is depicted in FIG. 16A.

Next, by means of handles 165, 149 and 168, the operator holds occlusiondevice 140 and push tube 163 substantially motionless while retractinghollow needle 161 backwards, away from the patient. Thus, the distal end164 of hollow needle 161 is retracted over occlusion device 140 and pushtube 163 until both anchors 142 and 143 are exteriorized from needle161. Anchor 143 is exteriorized distally to the lumen 151, and anchor142 is exteriorized proximally to the lumen 151. Each anchor assumes itsdeployed state following exteriorization. This situation is depicted inFIG. 16B.

It is noted that all absolute and relative motions of device 140, needle161 and push tube 163, may be made using an automated mechanism, suchas, for example, an automated electro-mechanical mechanism (not shown).

In the next step, by means of handles 165, 149, and 168, the operatorholds occlusion device 140 and needle 161 substantially motionless whileadvancing push tube 163 towards distal anchor 143. Push tube 163 thuspushes proximal anchor 142, causing it to slide towards distal anchor143. The operator continues to advance push tube 163 until proximalanchor 143 slides past separation point 146 and the distance betweenanchors 142 and 143 is sufficiently small as to flatten vessel 150 andannul its lumen 151, either totally or partially, as desired. Slidableanchor 142 is then locked in place and cannot slide proximally. Thissituation is depicted in FIG. 16C.

Next, the operator removes removable handle 149 from proximal part 144of occlusion device 140. The operator then exteriorizes from thepatient's body both needle 161 and push tube 163 over both distal part145 and proximal part 144 of device 140. The situation is depicted inFIG. 16D.

In the next step, the operator disconnects proximal part 144 of device140 from the remainder of the device. Disconnection may be brought aboutby, for example, unscrewing part 144 from part 145. If, for example,filament 144 of device 140 has an electricity-conducting core and aninsulating cladding everywhere except separation point 146, the operatormay separate parts 144 and 145 by running a sufficiently high electriccurrent in the filament. Finally, the operator exteriorizes part 144from the patient's body, which completes the implantation procedure(FIG. 6E).

It is understood that monofilament filtering devices according to someembodiments of the present disclosure are possible in which, in adeployed state, the proximal end of the monofilament extends exteriorlyfrom the patient's skin, or is implanted subcutaneously immediatelybelow the patient's skin. Such devices are particularly suited fortemporary usage, in which it is desired to retrieve the device shortlyafter a temporary embolus-enticing cause, such as surgery orminimally-invasive procedure, is removed.

In order to prevent stroke, filtering devices according to someembodiments of the present disclosure may be implanted in an arterysupplying blood to the brain, such an aorta, a common carotid artery, aninternal carotid artery, a subclavian artery, a brachiocephalic artery,or a vertebral artery.

In order to prevent pulmonary embolism, filtering devices according tosome embodiments of the present disclosure may be implanted in a veinsuch as a superficial femoral vein, a deep femoral vein, a poplitealvein, an iliac vein, an inferior vena cava, or a superior vena cava.

Implantation systems of some embodiments of the embolic protectiondevices described herein are possible, which are automatic and/orelectro mechanical.

The pusher in implantation systems according to the present disclosureneed not be solid: exteriorization of embolic protection devicesaccording to the present disclosure using pressurized fluid, liquid, orgas is possible.

Although a few variations of the embodiments have been described indetail above, other modifications to such embodiments are possible,enabling still other embodiments. For example, any logic flow depictedin the accompanying figures and/or described herein does not require theparticular order shown, or sequential order, to achieve desirableresults. Other implementations may be within the scope of at least someof the following exemplary claims.

Accordingly, exemplary embodiments of the devices, systems and methodshave been described herein. As noted elsewhere, these embodiments havebeen described for illustrative purposes only and are not limiting.Other embodiments are possible and are covered by the disclosure, whichwill be apparent from the teachings contained herein. Thus, the breadthand scope of the disclosure should not be limited by any of theabove-described embodiments but should be defined only in accordancewith claims which may be supported by the present disclosure and theirequivalents. Moreover, embodiments of the subject disclosure may includemethods, systems and devices which may further include any and allelements from any other disclosed methods, systems, and devices,including any and all elements. In other words, elements from one oranother disclosed embodiment may be interchangeable with elements fromother disclosed embodiments, thereby supporting yet other embodiments.In addition, one or more features/elements of disclosed embodiments maybe removed and still result in patentable subject matter (and thus,resulting in yet more embodiments of the subject disclosure).

1. A vascular embolic protection device for deployment at an implantation site within a blood vessel, the device comprising: a filament having a length, proximal and distal ends and a diameter between about 50 and about 500 microns, wherein the filament is configured to include an undeployed state and a deployed state, and wherein: in the undeployed state, at least a portion of the device is configured to fit within the lumen of a delivery tube; and in the deployed state, the device includes a primary axis which is approximately perpendicular to the blood flow direction.
 2. The device of claim 1, wherein at least one of the tube and the distal end of the device is configured for puncturing the blood vessel in the vicinity of the implantation site.
 3. (canceled)
 4. (canceled)
 5. The device of claim 1, wherein the filament further comprises a proximal segment near the proximal end and in the deployed state the proximal segment is substantially collinear with said primary axis.
 6. The device of claim 1, wherein at substantially every point along its length the radius of curvature exceeds a critical value equal to the diameter of the filament divided by about twice the critical strain of the material from which the filament is made.
 7. (canceled)
 8. The device of claim 1, wherein in the deployed state the filament has the shape of a helix comprising a plurality of turns.
 9. The device of claim 8, wherein the plurality of turns vary in diameter.
 10. The device of claim 8, wherein the number of turns is between one and twenty.
 11. (canceled)
 12. (canceled)
 13. The device of claim 8, wherein the distance between consecutive windings is greater than about 0.7 mm.
 14. The device of claim 8, wherein the distance between consecutive windings is less than about 1.5 mm.
 15. (canceled)
 16. The device of claim 1, wherein the filament is made from at least one of: a metal, a plastic, a natural polymer, a shape memory alloy, a super elastic alloy, a biodegradable material, a bioresorbable material, and a bioabsorbable material.
 17. The device of claim 1, further comprising an end piece at its proximal end, an end piece at its distal end, or both.
 18. The device of claim 17, wherein each of the end pieces comprises at least one of a radiopaque marker, an echogenic marker, a radioactive marker, a magnetic marker, a magnetic resonance marker, an anchor, a non-traumatic tip, a bearing, and a retrieval knob.
 19. (canceled)
 20. The device of claim 17, wherein at least one of end pieces comprises an anchor, and wherein the anchor comprises at least one of: a loop, a roughened surface, a barb, a micro-barb, a hook, a bulge, and a material configured to enlarge upon contact with an aqueous environment.
 21. (canceled)
 22. (canceled)
 23. (canceled)
 24. The device of claim 1, wherein the filament is substantially straight in the deployed state.
 25. The device of claim 1, wherein the shape of the filament is substantially similar in both the undeployed and the deployed states.
 26. The device of claim 1, further comprising two or more filaments, wherein each filament has a length, a diameter, a proximal filament end, and a distal filament end.
 27. The device of claim 26, wherein the filaments are joined at the proximal end and at the distal end of the device.
 28. The device of claim 26, wherein said two or more filaments each have a helical shape.
 29. The device of claim 1, wherein embolic protection is provided against stroke or pulmonary embolism, and wherein the patient's vessel is any of: an artery, a vein, an aorta, a common carotid artery, an internal carotid artery, a subclavian artery, a brachiocephalic artery, a renal artery, a vertebral artery, a superficial femoral vein, a deep femoral vein, a popliteal vein, an iliac vein, an inferior vena cava, or a superior vena cava.
 30. A method for providing embolic protection in a patient, the method comprising implanting a filament shaped approximately as a helix in a vessel of the patient, said vessel comprising a fluid flow, such that the axis of the helix is approximately perpendicular to the fluid flow direction. 